District



F. KNOOP.

yTOOL HOLDER.

APPLICATION man ris. 1e'. 1920.

1,41 5,578, Patented May 9, 1922.

'IIL

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volume of work isr small.

tempts have been'niadeto meet this need,

Unirse STATES P AT'ENToFFics.

FREDERICK KNOOP, OF WASHINGTON, DSTRICT ,OF COLUMBIA. f

`TOOL HOLDER. p

to cut threads of various angular pitches;

provision for the read;7 interchange of bits, of simple bar form, groundto cut threads eil' 'different torrns,`or specially shaped for otherclasses of work; and provision of a single means to lock the'bit inthecollet and loclr the collet in the holder so that the adjusting meanscan never be subjected to heavy stress incident to the cutting action ofthe tool.

Subordinate features of the invention reside in the `forni andarrangement of the parts, and provide a tool of simple rugged forni,devoid of large projections, particularlv lateral projections', andyhaving the resilient goose neck so desirable for smooth thread cutting.n n

There has long been yneed for angularly adjustable threading tools foruse in tool rooms, model shops and other shops vwhere the ythread formsare numerous and the li-leretoifore atbut have resulted in cumbersomeand inconvenient devices, requiring special and intricate forms ofcutter, and entailing undesirable methods of use f The tool holderprovided by the present invention uses straight bar bits, inexpensiveto' make troni any steel (including high speed steels) the cuttingoperation is the saine as with any lstandard threading tool; and the:torni and dimensions oit the complete holder closely approxiinatethoseostandard 'tool holders lacking the adjustment feature.

An embodiment of theinvention success`` fully used by meis illustratedinthe drawings, in which i" l Fig. 1 is' a side elevation of thekcon'iplete device, with the bit or cutter in position; Fig. 2 is a planView of the same,

QO'threa-ded in head 9. groove 18 the collet 11l is cut traiisversel,T

`tornisa clamping-tongue 211.

specification of Leiters Patent,A Panted Mm; 9, m22

d (41 a Application fried February ie, 1920. seriai No. 358,395.'

. Fig. 3 is a longitudinal vertical section throughthe head of theholder, showing' the angularly adjustable collet and the clampingmeans;Y l

Fig. is a section on the line i--l 'of Fig. 3;

n. Y nig. 5 is a side elevation of the collet removed fromA the holder;

`llfig. e is a` plan hview of a special cutter designed for use incutting threads to a shoulder; and 'Fig. 7 is a section on the line T-Toir l* ig.

w The shank` of the tool holder, which is held in the Ltoolpost of thelathe, is shown 8; This terminates at its forward end in head 9, agoose-neck portion 10 beiner This'holds the collet against endwiseniovenient.` Y The. collet 11 has a rectangular tool extends the entirelengtliot the collet. The Isocket 15 is designed to 'embrace closely aninserted rectangular bit 16 Whose end 17 is `ground to out the' desiredthread torni. The

bits may be reversible, and ground at each fiend, andare so shown.

The collet 11v is formedv with Va surrounding groove 18 within whichfits the 4clamping` hlocl; 19. This is actuated bv clamp screw At eitherside of part way'through, as shown at 21 and 2Q,

and these cuts are connected by a longitudinal cut 23', leaving aresilient portion ywhich y lh'en the screw 20 is set down the block 19is 'forced wagainsttongued and siniultaneouslT locks f bit '1.6 incollet 11 and locks collet`11 against rotation.'y

' Theworm wheelsector 13 is actuated by' `a wormr25; This turns in astep bearing 26 in 'goose neck lOarid is also swiveled in a plate 27held tofgoose neck 10 by screws 28.

The'wormQfcarries a graduatedv'head 29 p "socket 15, which for ease ininanutacture.

whose graduations are read against an index 30 on plate -T and indicatethe angular position of collet ll. The marks L and R on plate 27,respectively indicate the direction of adjustment from the zero positionof the collet for left hand and right hand threads. Since the adjustmentof collet il for quick pitch threads requires several turns of worm 25,index lines 31 are placed on the flange 12 of collet 11 and on head 9 toindicate by their register the zero position of the collet. To avoid thepossibility of injury to the worm and worm wheel sector by forciblyturning the worm while the collet is clamped, the milled head 32 ispurposely made small so as to offer a poor hold. To reduce backlash theworm wheel is slotted at 33 and so mounted that the two sides of thesector embrace the worm resiliently.

When threading to a shoulder, I use a bit such as shown. in Fig. 6. Withthis bit the shank of the tool holder is set at an angle.

The proper angle of adjustment for any thread may be readily determined.A tabulation of adjustments for all standard threads should be provided,and special cases may be solved by the use of a simple 'formula and atable of natural tangents.

The head 29 is graduated in degrees of angle of adjustment of thecollet, one turn of the worm producing an adjustment of the collet offour degrees. Any other suitable ratio of adjustment might be used, but1 -find this to be convenient and to give satisfactory' dimensions ofthe worm and worm wheel sector.

The manner of using the tool holder is obvious to those skilled in theart. An important feature of the device is that since the coll-et l1 isclamped against turning by the act of clamping the bit in the collet.and since the bit cannot cut unless clamped in the collet, the wormadjusting mechanism can never be subjected. even by inadvertence, toheavy stress. This feature allows the use of a small adjusting mechanismand greatly reduces the size and improves the form of the tool.

' The clearance at the rear of Worm wheel sector 13 need be only a fewthousandths of an inch to accommodate the necessary yielding of thegoose neck 10, and this clearance is preferably made as small asconveniently possible to reduce the size of the tool holder to aminimum.

Various minor modifications may be made without departing from thespirit of the invention. The graduated head and the worm reduction gearform in eifect an indexing head for the collet kand tool, i. e.,

an accurate positive indicating and adjusting mechanism. The effectiveelements are, broadly, some type of graduated dial and a suitablereduction gear, but I prefer the worm and graduated head for thesimplicity, compactness and maintained accuracy.

lVhat is claimed is:

1. in a threading tool, the combination ot a tool stock; a cutting toolmounted upon said stock and capable of angular adjustment thereon toadapt it to cut threads of different angular pitches; adjusting meansfor said tool including a dial and a reduction gear; and a clamp actingbetween the stock and tool and serving to clamp the tool to the stock inits adjusted positions.

2. In a threading tool, the combination of a tool stock; a cutting toolmounted upon said stock and capable of angularadjustment thereon toadapt it to cut threads of different angular pitches; adjusting meansfor said tool including a worm reduction gear; and a clamp actingbetween the stock and tool, independent of the worm reduction gear, andserving to lock the tool to the stock in its angularly adjustedpositions.

3. In a threading tool, the combination of a tool stock formed with agoose neck; a cutting tool mounted upon said stockA and capable ofangular adjustment thereon to adapt it to cut threads of differentangular pitches; adjusting means for said tool including a dial and areduction gear housed within said goose neck; and a clamp acting betweensaid stock and tool. and serving to clamp the tool to the stock in itsangularly adjusted positions.

4. In a threading tool, the combination of a tool stock; a tool holdingmember mounted upon said stock and capable of angular adjustment thereonto set tool held thereby to cut threads of diii'erent angular pitches;adjusting means for said memben.

including a dial and a reduction gear; and

clamping means acting directly between said stock and said member andserving to lock said member to said stock in its angularly adjustedpositions.

5. In a threading tool. the combination of a tool stock formed with agoose-neck; a tool holding member mounted upon said stock and capable ofangular adjustment thereon to set the tool held thereby to cut threadsof different angular pitches; adjusting means for said member includinga dial, and a reduction gear housed in said goose neck; and clampingmeans acting directly between said stock and said member and serving tolock said member to said stock in its angularly adjusted positions.

6. In a threading tool, the combination of a tool stock; a colletmounted in said stock and capable of angular adjustment therein; acutting tool mounted in said collet, the angular adjustment of thecollet servingto set the tool to cut threads of different angularpitches; adjusting means serving to adjust the angular position of thecollet,

said means including a dial and a reduction gear; and a single clampingmeans serving to clamp the the collet upon the tool and to lock thecollet in said stock against movement from its adjusted position.

7. In a threading tool, the combination of a tool stock formed with agoose neck; a -p collet mounted in said stock and capable ofangularadjustment therein; a kcutting tool mounted in said collet, theangular adjustment of the collet serving to set the tool to cut threadsof different angular pitches; a Worm reduction gear housed in said gooseneck and serving to adjust the angular position of said collet; and asingle clamping means serving to clamp the collet upon the tool and tolock the collet in said stock against movement from its adjustedpositions.

8. A threading tool holder, comprising in combination, a goose neckstock; a tool clamping collet angularly adjustable in said stock; anindexing head serving to adjust the angular position of said collet; andmeans for clamping the collet.

9. A threading tool holder, comprising in combination, a tool stock; acollet capable of angular adjustment in said stock and having a portionadapted to be clamped upon an inserted tool; an indexing head serving toadjust the angular position of ysaid collet; and a single clamping meansserving to clamp the collet upon an inserted tool and to hold the colletagainst movement 'from its adjusted position.

l0. A threading tool holder, comprising in combination, a ytool stock; arigid cylindrical collet capable of angular adjustment in said stock toset the holder for thread cutting at different angular pitches, saidcollet having a flexible integral tongue adapted to be clamped upon aninserted tool Without substantial deformation of the remainder of thecollet; and a single clamping means serving to cla-mp said tongue upon atool inserted in the collet and simultaneously to hold the colletagainst movement from its adjusted osition.

ll. A threading tool holder, comprising in combination, a tool. stock; arigid cylindrical collet capable of angular adjustment in said stock tosct the holder for thread cutting at diilerent angular pitches, saidcollet having a flexible integral tongue adapted to be clamped upon aninserted tool Without substantial deformation of the remainder of thecollet; a single clamping means serving to clamp said tongue upon a toolinserted in the collet and simultaneously to hold the collet againstmovement from its adjusted position; and a motion-multiplying indicaterserving to indicate the angular adjustment of said collet.

l2. A threading tool-holder comprising in combination, a stock; a toolclamping collet angularly adjustable with reference thereto; a -niotionmultiplying indicator serving to indicate the angular adjustment of saidcollet With reference to said stock; and means for clamping the colletin its adjusted positions.

13. A threading tool-holder comprising in combination, a stock; a toolangularly adjustable With reference thereto; a motion multiplyingindicator serving to indicate such angular adjustments of said tool; andmeans 'serving to lock the tool in its angularly adjusted positions.

In testimony whereof I have signed my name to this specification.

FREDERICK KNOOP.

